IBM 6150 Hardware Maintenance Manual page 183

TNL SN32-9004 (August 87) to 75X0152 or 75X0166
Step 23
The following FRUs are the most likely to cause a keyboard failure.
Exchange the FRUs that have not been exchanged in the following order.
Test each FRU by running System Checkout. If you identify a failing
FRU, use the removal and replacement procedures in the section that
applies to the FRU and exchange it, then go to "Step 25" on page
3-0060-26. If you cannot identify a failing FRU, contact your service
support person.
1. The keyboard.
2. The system board.
3. The processor board.
4. The power supply.
5. The display adapter.
6. An adapter for the fixed-disk and diskette drive.
7. A memory expansion option in slot C.
8. The IBM AT High Capacity Diskette Drive.
9. The cables for the fixed-disk and diskette drive.
10. The cooling fan.
11. The display.
3-0060-24 Service Manual